feat(search): P3.1 filters and multi-query merge

Native include/exclude domains, time_range, topic, exact_match, min_score,
and up to 4 queries fused with RRF. Honesty notes stay off the Warn/fail
path. Tavily keeps include_answer false and sets auto_parameters false.
Cache key is canonical JSON. CLI flags and skill recipe included.

README.md

@@ -19,7 +19,7 @@ The server binds `127.0.0.1:8890` and is published on the tailnet by `tailscale
 | `POST /v2/scrape` | Firecrawl-compatible fetch (`url`, `formats`) — what Hermes `web_extract` calls |
 | `POST /v2/search` | Firecrawl-compatible search (`query`, `limit`) — what Hermes `web_search` calls |
 | `POST /v1/fetch` | native fetch: `url`, `mode` (`clean`/`raw`/`digest`), `question`, `jq`, `context`, `recover`, and for PDFs `pages`, `grep` |
-| `POST /v1/search` | native search: `query`, `question`, `k`, `rerank`, `digest` |
+| `POST /v1/search` | native search: `query` or `queries`, `k`, `rerank`, `digest`, domain/time/topic/`exact_match`/`min_score` |
 | `GET /metrics`, `/metrics.json` | Prometheus text or JSON; open on loopback, bearer elsewhere |
 | `GET /healthz` | liveness |
 
@@ -34,7 +34,7 @@ sift serve  [-listen addr] [-config /etc/sift/config.toml] [-keys /var/lib/sift/
 sift fetch  <url> [--question q] [--mode clean|raw|digest] [--jq filter] [--pages a-b] [--grep re]
                   [--no-context] [--recover] [--json]
 sift extract <file.pdf> [--pages a-b] [--grep re] [--question q] [--mode clean|digest] [--json]
-  sift search   "<query>" [--k n] [--json]
+  sift search   "<query>" [--k n] [--json] [--include-domain host]... [--topic news] [--time-range month]
   sift batch    submit|status|get|cancel
   sift keys   add --caller name [--workspace ws] [--out file] | list | revoke --caller name
   sift version